The rotary connector device mounted on a vehicle such as automobiles and the like includes a cable housing formed of a stator and a rotator to be assembled on a same axis so as to be relatively rotatable.
The rotary connector device has the stator secured to the automobile body and the rotator assembled on the steering wheel in the cable housing, and electrically connects a horn module, air bag module, power supply, and the like, for example, between the automobile body and the steering wheel.
In recent years, a rotary connector device comprising a retainer which is located on a bottom surface of an accommodating space and which guides the cable to rotate around a shaft of a steering has been proposed. With such a retainer, the cable wound in a circle in the accommodating space can smoothly move so as to follow a rotating operation of the steering.
A rotary connector device in Patent Document 1 is one of the rotary connector devices comprising retainers (moving bodies) as described above.
The retainer of Patent Document 1 is formed of a plurality of rollers and a ring-shaped rotating plate, and the rotating plate is placed on a bottom plate which forms a bottom surface of the accommodating space. An inner peripheral edge portion on an upper surface of the rotating plate and a lower edge portion of an inner peripheral tube portion (upper rotor) which forms an inner peripheral surface of the accommodating space abut each other planarly (see FIG. 3 in Patent Document 1).
When a steering rotates, the rotating plate and the inner peripheral tube portion respectively rotate around a shaft of the steering with edge surfaces which planarly contact each other sliding against each other.
In this example, since the abutting portions have planar shape, areas of the abutting portions are large. Smooth rotation is inhibited and it becomes impossible to guide rotation so as to follow movement of the cable. As a result, there are problems that a contact resistance between the cable and the retainer become large and cause abrasion, and that a load such as tension received by the cable from the retainer becomes large and cause the cable to be broken.